import { HttpClient, HttpHeaders } from '@angular/common/http';
import { Injectable } from '@angular/core';
import { Observable } from 'rxjs/Observable';
import 'rxjs/add/operator/map';
import { Task } from '../../pages/tasklist/task';


@Injectable()
export class HttpDataProvider {

  private readonly baseUrl: string = 'https://api2.bmob.cn/1';
  private readonly httpOptions: Object = {
    headers: new HttpHeaders({
      'X-Bmob-Application-Id': '36ccd9138e86c836bc520be27d052f0c',
      'X-Bmob-REST-API-Key': '3a27a438dc5e7b3936a1c6a687da8c70',
      'Content-Type': 'application/json',
    })
  };

  constructor(public http: HttpClient) {
    console.log('获取HTTP数据服务加载');
  }
  /**
   * 获取待办事项列表
   * @returns {Observable<Task[]>} 待办事项列表数据集合
   */
  getTaskList(): Observable<Task[]>{
    return this.http.get<Task[]>(`${this.baseUrl}/classes/ToDoList`, 
    this.httpOptions).map(data => data["results"]);
  }

  /**
   * 获取指定待办事项
   * @param objectId 
   * @returns {Observable<Task[]>} 待办事项
   */
  getTask(objectId: string): Observable<Task>{
    return this.http.get<Task>(`${this.baseUrl}/classes/ToDoList/ToDoList/${objectId}`,this.httpOptions);
  }

  /**
   * 新增待办事项
   * @returns {Observable<Task[]>} 响应结果
   * @param task 
   */
  addTask(task: Task): Observable<Task>{
    let _task = {title: task.title, status: task.status, description:task.description};
    return this.http.post<Task>(`${this.baseUrl}/classes/ToDoList/`, _task, this.httpOptions);
  }

  /**
   * 更新指定的待办事项
   * @returns {Observable<Task>} 响应结果
   * @param task 
   */
  updateTask(task : Task): Observable<Task>{
    let _task = {title: task.title, status: task.status, description:task.description};
    return this.http.put<Task>(`${this.baseUrl}/classes/ToDoList/${task.objectId}`, _task, this.httpOptions);
  }
  /**
   * 删除指定待办事项
   * @param task 
   */
  deleteTask(task : Task): Observable<{}>{
    return this.http.delete(`${this.baseUrl}/classes/ToDoList/${task.objectId}`, this.httpOptions);
  }
}
